<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      class Person {
        static uname = "jack";
        static age = 20;
        static say() {
          console.log(this.uname);
        }
        username = "lili";
        jump() {
          console.log(this.username, "jump");
        }
      }

      class Admin extends Person {}

      // console.log(Admin.uname);
      // Admin.say();
      console.dir(Person);
      console.dir(Admin);
      console.dir(Admin.__proto__ === Person);
    </script>
  </body>
</html>
